The present invention generally relates to surgical instruments and methods of suturing tissue.
A number of diagnostic and treatment procedures are conducted intravascularly. Typically, a catheter is introduced into the vascular system at a convenient access location and is then guided to the target treatment site. The Seldinger Technique is one of the well-known early examples of this type of procedure which can include catheterization and angioplasty techniques. Procedures such as this require a vascular access. Typically an introducer sheath with or without a guide wire is inserted through a puncture wound in a vessel such as the femoral artery at a location near the groin. A catheter and other instrumentation can then be inserted through the sheath and guided to the targeted treatment site. After the diagnostic and/or treatment procedure has been completed, the puncture wound must be closed. Closing the wound can be difficult because of the substantial bleeding that can occur through an open wound in the vascular vessel. One technique for hemostasis includes applying pressure near or upstream of the puncture site. This approach suffers from many deleterious effects, not the least of which are that it can be time consuming and extremely uncomfortable—even painful—for the patient because the pressure is applied directly on or adjacent to the traumatized site. Frequently anticoagulants are employed for the original diagnostic/treatment procedures. This delays clot formation during the procedure, and this effect lasts through the initial recovery period, lengthening the time during which pressure must be applied to the wound for up to twelve hours or more. During this initial recovery period, it is imperative that the patient remain still, further adding to the patient's discomfort.
Alternatively, the puncture wound can be closed with sutures. This can be extremely difficult because the vascular vessel with the puncture lies underneath the patient's outer skin. Some vascular vessels, notably the femoral artery, appear to be relatively large; however, in practice, even the largest arteries cannot be readily sutured. Therefore, devices have been developed to facilitate subcutaneous suturing of arteries and veins. These devices can extend through the outer tissue to the puncture wound in the vascular vessel. Needles are then deployed from the device to suture the tissue adjacent the puncture wound.
Certain devices are inserted through the wound and initially deploy a needle to pierce the tissue in from outside the vascular vessel and continue on into a receptacle in the portion of the device located within the lumen of the vessel. The suturing device can be removed from the vessel (and the patient) by withdrawing the needles and suture material at the same time. However, under certain conditions the needles may not be fully captured within the depository or the needles can become dislodged upon removal of the device from the patient. This can be particularly prone to occur when the needles remain attached to the suture material. For example, as the device (with the suture attached to needles) is withdrawn, friction from drawing the suture material through tissue tends to pull the needles out of the depository. In any event, the dislodged needles catch on tissue. This can result in snagging and possibly tearing of the vascular tissue or the upper tissue layers depending upon when the needles become dislodged.
In view of the above background, there remain needs for improved and/or alternative methods and devices for closing vascular opening or punctures. The present invention is addressed to these needs.